What is a Powerball Premium ABS It is an inflatable and burst proof gymnastic ball with an ABS Anti Burst System. The material called Crylon is odorless and very resilient (load up to 1000 kg/ ABS guarantee up to 170 kg). It is free of latex and contains no forbidden phthalates. What is it good for It offers safety while sitting or performing exercises due to its ABS System which makes it guaranteed burst proof up to a 170 kg of dynamic load (See Explanation below). Sitting on the Powerball ABS can help to avoid back pain through an upright posture and counterbalancing moves of the body. Abdominal and back muscles can be strengthened through safe, efficient, and dynamic back and stability exercises. How does it work While sitting on the ball an upright posture is assumed almost automatically by the upper body. At the same time the pelvic floor-, abdominal and back muscles are inevitably being used to counterbalance the body. This permanent activity strengthens the muscles. Explanation ABS and Burst Proof The ABS System is a special molecular composition of the surface that prevents the ball from bursting even when damaged or penetrated by a sharp object. The molecular structure does not allow a whole to grow rapidly faster and rip the ball apart. In case of any damage the ball looses air slowly and leaves enough time for its user to get off safely. There is a difference between the total load a ball can withstand when not damaged, and the maximum load that is allowed for the ball to stay burst proof even when harmed by an object. The Powerball Premium ABS can withstand 1000 kg undamaged and is guaranteed burst proof up to 170 kg when it becomes damaged. This weight is considered being dynamic, that means a person sitting and moving on the ball can weigh up to 170 kg. Hint: "Many people think one ball is like the other. We are seldom wasting any thoughts on what could happen when a ball is damaged and bursts while we are still sitting or exercising on it